DIPNECH is pre-invasive precursor to carcinoid tumors and tmorlets, most of which present with pulmonary symptoms. We present a case of ectopic cyclical ACTH producing DIPNECH.
33-year lady presented with a short history of weight gain, abdominal striae, proximal myopathy and secondary amenorrhoea. She reported a previous episode with similar symptoms one year earlier which resolved spontaneously after a few weeks. Random cortisol 4000 nmol/l, ACTH 98 ng/l. LDDST failure to suppress cortisol levels. IPSS showed no central:peripheral ACTH gradient, representing ectopic ACTH source. CT chest showed multiple pulmonary nodules, a dominant RLL nodule larger since 2006. 68-Gallium DOTATATE PET/CT scan was normal. Metyrapone was commenced. One week later, Metyrapone was stopped due to low cortisol levels. Off Metyrapone, cortisol levels remained low with concomitant reduction of ACTH levels, indicating another spontaneous remission of Cushings syndrome. Histology from an excision biopsy of the RLL nodule revealed tumourlets with a typical carcinoid appearance and a background of DIPNECH. Post-operatively, she was treated with hydrocortisone replacement for a couple of weeks. After a few months later symptoms of Cushings recurred and repeat imaging of the chest has not shown any progression of the lung nodules. Repeat LDDST confirmed the biochemical excess of cortisol. She is currently awaiting bilateral adrenalectomy.
As per the literature review, DIPNECH is common in female. There is only one case presented with ACTH secretion. It is relatively a stable disease with only 26% of the patients deteriorates clinically and radiologically. Octreotide has not shown to improve the prognosis.
20 May 2017 - 23 May 2017